1. Field of the Invention
The present invention relates to a back cover and a method of assembling back cover method. The invention relates more particularly to a technical field in which a cover main body and a case member are connected together by an elongated seal projection which is bonded in such a state the projection is fitted in a seal groove so as to realize an improvement in mounting strength with which the case member is mounted on the case main body as well as an improvement in waterproofness therebetween.
2. Background Art
There are vehicle lamps in which a light source and an illumination circuit (a ballast) for driving the light source are disposed in a lamp chamber defined by a front cover and a lamp body (for example, refer to JP-A-2008-277008).
A vehicle lamp described in JP-A-2008-277008 has a cover main body which is formed from a resin material and a heat dissipating member which is formed of a metallic material and functions as a case member, and a heat dissipating member mounting portion formed into a frame-like shape is provided on the cover main body. The heat dissipating member is fitted inside the heat dissipating member mounting portion and is mounted on the cover main body by an outer circumferential portion thereof being bonded, for example.
However, in the back cover described in JP-A-2008-277008, since the heat dissipating member (the case member) is mounted on the cover main body by being fitted in the heat dissipating member mounting portion and being bonded therein, there is a fear that a gap is produced between an inner circumferential surface of the heat dissipating member mounting portion and an outer circumferential surface of the heat dissipating member.
When such a gap is produced, there is caused such a drawback that a light source illumination circuit is badly affected or that a front cover is clouded up by water which infiltrates a lamp chamber whose waterproofness is reduced. In addition, there is caused such a drawback that the mounting strength with which the case member is mounted on the cover main body is reduced to thereby produce looseness or that the heat dissipating member falls from the cover main body.